Genetic structure and differentiation at a short-time scale of the introduced calcarean sponge Paraleucilla magna to the western Mediterranean

Abstract

The allochthonous calcarean sponge Paraleucilla magna has proliferated in the western Mediterranean during the last decade, where it currently shows a highly patchy distribution with dense populations in the neighboring of sea farms and slightly eutrophised marinas, and more sparse populations in well-preserved habitats. To gain knowledge about the species invasive capacity, we studied spatial genetic differentiation and structure, clonality, and temporal differentiation, in three close populations of P. magna at the NE of the Iberian Peninsula, in three successive years. The study hypothesis was that the species is able to proliferate under favorable conditions in newly colonized habitats but populations can easily disappear where perturbations occur with some frequency. Samples were genotyped for nine polymorphic microsatellites. Spatial genetic structure was found in the three populations of 2006. One population disappeared in 2007, and the other two remained slightly differentiated, while the three populations were in place again in 2008, and showed very low (but significant) F ST values, and non-significant D values. Low but statistically significant differentiation also occurred for the three populations between years. Results showed high-allele diversity, but heterozygote deficit and changes in allele frequencies in the populations over the 3 years, which are consistent with some genetic drift. The whole population descriptors pointed to the species as a good opportunistic colonizer as it has been hypothesized, but highly sensitive to stochastic events affecting recruitment. This suggests a high impact of the species in favorable habitats (sea culture and sheltered zones) and a low-medium influence in native communities.

Implications of population connectivity studies for the design of marine protected areas in the deep sea: An example of a demosponge from the Clarion‐Clipperton Zone

“…The genetic diversity values found in our study are within the range of other studies on marine sponges using microsatellite markers. Comparisons with data available in these studies (Duran, Pascual, Estoup, & Turon, 2004;Blanquer, Uriz, & Caujapé-Castells, 2009;Blanquer & Uriz, 2010;Dailianis, Tsigenopoulos, Dounas, & Voultsiadou, 2011;Guardiola, Frotscher, & Uriz, 2012, 2016Bell et al, 2014;Pérez-Portela, Noyer, & Becerro, 2015;Giles, Saenz-Agudelo, Hussey, Ravasi, & Berumen, 2015;Chaves-Fonnegra, Feldheim, Secord, & Lopez, 2015;Riesgo et al, 2016;under…”

Fragmentation, Fusion, and Genetic Homogeneity in a Calcareous Sponge (Porifera, Calcarea)

“…Fragmentation has been suggested to be a strategy that prevents the spread of pathogens, increases chances of dispersal, and deals with energetic constraints on growth. Alternatively, it may be a physiological response that increases the chances of genotype survival after changing environmental conditions, events of partial mortality and population decrease in sponges (Reiswig, '73;Sebens, '87;Gaino et al, '91;Wulff, '91;Tanaka, 2002), corals, and other marine invertebrates (Hughes and Jackson,'80 and references therein (Guardiola et al, 2011;Cavalcanti et al, 2013). Clathrinid sponges (such as Clathrina and Borojevia) and Paraleucilla magna have largely different external body morphology, aquiferous system, and skeletal organization, suggesting that the organization and shape of calcareous sponges may affect their ability to undergo fragmentation and fusion.…”

Environmental effects on the reproduction and fecundity of the introduced calcareous sponge Paraleucilla magna in Rio de Janeiro, Brazil

“…The periodicity of the reproduction of P. magna appears to vary according to the locality and even the year. Lanna et al (2007) and Guardiola et al (2012) showed that the reproduction of this species is restricted to the warmer months of the year in Rio de Janeiro and in Spain, respectively, while Longo et al (2012) and Padua et al (2013a) observed continuous reproduction throughout the year in Italy and Rio de Janeiro, respectively, with peaks during summer.…”